﻿#include <iostream>

using namespace std;

int fibonacci(int n);

int main()
{
    int n;
    cin >> n;
    cout << fibonacci(n);
}

int fibonacci(int n)
{
    if (n == 0 || n == 1) {
        return 1;
    }
    else {
        return fibonacci(n - 1) + fibonacci(n - 2);
    }
}
